Apparatus for recovering waste gases in a refinery



Sept. 21, 1965 R. E. GLADIEUX APPARATUS FOR REGOVERING WASTE GASES IN A REFINERY Filed Nov. 24. 1961 GASOLINE INVENTOR. RALPH E. GLADIEUX 7/d, M qJu'kb l N U m A momzmazou e w S m m m v E23 wzfizopom R o E M 4 m mm u m m C .H T S B ATTORNEYS United States Patent 3,207,675 APPARATUS FOR RECQVERING WASTE GASES IN A REFINERY Ralph E. Gladieux, Fort Wayne, Ind, assignor of onehalf to James Morris Gladieux, Fort Wayne, Ind. Filed Nov. 24, 1961, Ser. No. 154,777 3 Claims. (Cl. 196-98) The present invention relates to the art of distilling liquid hydrocarbon fuels and more particularly to the utilization of by-product vapors and gases which are normally wasted into the atmosphere.

In the fractional distillation of fuels such as gasoline and jet fuel, certain gases (normally referred to as ends) are produced as waste or by-products and as such they are wastefully vented into the atmosphere. These gases are usually separated from the finished product (gasoline, fuel oil, jet fuel or the like) near the end of the distillation process, the finished liquid product being conveyed to a storage vessel and the gases being conducted in another direction and wasted into the atmosphere.

The present invention is unique for the reason that these wasted gases are recirculated back into the start of the distillation process, and more particularly are fed to the burner of the still in which crude oil is first heated and transformed into vapors. As is well known, fuel is burned to provide the necessary heat in the still, such fuel being in the form of fuel oil, commercial gas or the like, and as such being an item of expense. In this invention, such fuel is saved, or in other words is not used, it being replaced by the ends or gases which were previously wasted into the atmosphere.

Up to the present time, such by-product gases have not been utilized as fuel because of the danger of ignition and flashback into the distillation system, which could cause a disastrous fire. Other reasons exist, which need not be elaborated on here, as to why such gases have not heretofore been used in performing useful work.

It is therefore an object of this invention to provide apparatus for utilizing efiiciently the by-product gases produced in the fractional distillation of liquid fuels.

It is another object to heat the still of a distillation system by means of the gases which are normally wasted into the atmosphere as an unwanted product of the distillation process.

Other objects will become apparent as the description proceeds.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a flow diagram of a typical refinery equipped with an embodiment of this invention whereby waste gases are efficiently utilized by returning them to the burner for the still; and

FIG. 2 is a partial illustration of the apparatus of this invention shown partly in section and partly in diagram.

Referring to the drawings and more particularly to FIG. 1, a typical refinery used in the production of ordinary gasoline is illustrated as comprising a still having a burner 12 as a part thereof, a fractionating tower 14, and a condenser 16. In operation, ordinary crude oil is fed to the still 10 in the usual manner and is elevated in temperature by the burner 12 to a point at which it is converted into a vapor which is conducted by means of a line 18 to a fractionating tower 14. From the fractionating tower 14 via a line 20 connected to the top of the tower, gasoline vapors are conducted to the upper end of an ordinary condenser 16 in which the gasoline vapors are condensed and transformed into liquid. This liquid gasoline is conducted from the bottom of the condenser 16 by means of a line 22 to a storage tank 24.

Jet fuel, or in other Words fuel used in the operation of jet aircraft, is refined and processed in generally the same manner; however, this process includes certain cleaning and refining steps which are not shown in FIG. 1 but which are conventional insofar as the refining art is concerned. While the present invention is applicable to the refining of any end product liquid fuel, the use in connection with the refining of liquid gasoline will suffice for purposes of teaching the invention.

Again referring to FIG. 1, in the processing of the gasoline which is eventually conveyed to the storage tank 24, certain light ends or vapors are generated which do not condense into liquid but instead build pressure in the storage tank 24 or the line 22 to a point at which they must blow off. These gases or vapors are normally allowed to vent into the atmosphere and are therefore wasted. These gases are combustible; hence, every care must be exercised in preventing the ignition up in vapor thereof to prevent flashback through the system and a resulting fire.

In the present invention, the light ends or by-product gases are conveyed via a line 26 to a trap indicated generally by the reference numeral 28. This trap is shown in somewhat greater detail in FIG. 2, and comprises a -shaped conduit having two upstanding arms 30 and 32 which are connected at the bottom thereof by a one-way check valve 34. As shown in FIG. 1, the upper end of the arm 30, is connected to the line 26 while an expansion tank 36 is connected to the upper end of the arm 32.

The upper end of the expansion tank 36 is connected by means of a pipeline 38 to a condensation tank 40, the upper end of the pipe 38 opening just through the wall of the tank 40. A vent pipe 42 is fitted inside the tank 40 in an upright position with the upper end 44 thereof terminating just short of the top of the tank 40. The opposite end of the pipe 42 is connected to a vacuum pump 46 of conventional design with the outlet of this pump being connected by means of a pipe 48 back to the burner 12 of the still, as shown in FIG. 1.

The trap 28 which includes the expansion tank 36 is filled with No. 2 fuel oil in a preferred embodiment of this invention to the level indicated by the numeral 50. Thus, the one-way check valve 34 is normally submerged in this fuel oil. While No. 2 fuel oil has been specified, it will become obvious to a person skilled in the art that any similar liquid may be used without departing from the spirit and scope of this invention.

In operation, the by-product light ends or gases are conducted from the line 22 in storage tank 24 via the line 26 to the upper end of the trap arm 30. These gases continue their movement through the trap 28 by bubbling through the No. 2 fuel oil into the expansion tank 36 from which they pass upwardly into the condensation tank 40. The vacuum pump 46 is continuously operated and pulls or draws the gases through the trap 28, the tanks 36 and 40, and then pumps them outwardly through the line 48 back to the burner 12. The burner 12 burns these gases, which in turn produces the necessary heat in the still 10 for transforming the liquid crude oil into vapor.

The one-way check valve 34 is so designed as to open in the direction of flow indicated by the arrow F under the reduced pressure as produced by the vacuum pump 46 such that the gases travel in only one direction, from right to left, as viewed in FIG. 2. They continue to flow outwardly through the expansion tank 36 and condensation tank 40, vacuum pump 46, and finally to the burner 12.

The No. 2 fuel oil in the trap 28 does not impair in any Way the combustible properties of the gases which are bubbled therethrough. If water were used instead of the fuel oil, water vapors would mix with the gases and would thereby impair the combustibility thereof. Therefore, the liquid that is used in the trap 28 should be of such composition as will not impair the combustible properties of the gas and, secondly, will not vaporize appreciably to such an extent as to be lost after a short period of operation.

One of the purposes served by the trap 28 and the fuel oil therein is the prevention of flashback into the system such as the storage tank 24 and line 22 in the event the gases in the pipe 38 should ignite. Such a flashback could prove disastrous. Also as a guard against flashback into the system is the one-way check valve 34. If the gases in the pipe 38 or environs should ignite, a mild explosion would result, which would tend to drive the fuel oil in the trap 28 backwardly through the conduit 26 and into the storage tank 24. However, the one-way check valve 34 would immediately close and not only prevent the flow back of the fuel oil but would also prevent the fire from flashing rearwardly through the system and eventually into the storage tank 24 and condenser 16.

The one-Way check valve 34 may be conventional, but in the illustrated embodiment it comprises a poppet valve 52 which normally engages a valve seat 54 under the force of a helical spring 56. As the pump 46 is operated, the differential pressure developed over the poppet valve 52 is suflicient to lift it off the valve seat 54, permitting the gases to bubble therethrough and upwardly into the expansion tank 36.

One of the purposes of the condensation tank is to prevent any of the gases which may eventually liquefy from being conducted to the vacuum pump 46 and also to the burner 12 which is adjusted to burn gas instead of liquid.

From the foregoing, it will be apparent that the present invention efliciently utilizes the gases and vapors (referred to in the art as light ends) by burning them in the still, the trap 28 serving to prevent any flashback into the distilling system in the event the gases should ever ignite. This utilization of the gases which were formerly wasted obviously results in great savings in connection with the cost of fuel which is normally burned to operate the still 10.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention.

What is claimed is:

1. A fuel oil distillation plant comprising fuel-processing apparatus having a burner, said apparatus including first means for producing a liquid end product and a byproduct combustible gas, a U-shaped trap having two end connections, second means coupling one of said end connections to said first means for directing said gas to said trap, said trap being filled with a non-volatile hydrocarbon liquid, a one-way check valve in said trap positioned to permit fluid flow in only the direction from said one end connection to the other end connection, and a pump having an inlet connected to the other end connection and an outlet connected to said burner, whereby gas produced by said first means is returned to said burner for combustion and heating of said apparatus.

2. A fuel oil distillation plant comprising fuel-processing apparatus having a burner, said apparatus including first means for producing a liquid end product and a byproduct combustible gas, a U-shaped trap having two end connections, second means coupling one of said end connections to said first means for directing said gas to said trap, said trap being filled with a non-volatile hydrocarbon liquid, a one-way check valve in said trap positioned to permit fluid flow in only the direction from said one end connection to the other end connection, and third means for conducting said gas from said other end connection to said burner.

3. The distillation plant of claim 1 wherein said hydrocarbon liquid is No. 2 fuel oil.

References Cited by the Examiner UNITED STATES PATENTS 278,045 5/83 Reich 137--247.17 X 441,751 12/90 Crowner 137-24717 1,093,722 4/14 Osbourn 137-247.15 1,160,689 11/15 Burton 137247.15 X 1,183,091 5/16 Lucas 196-134 X 1,536,127 5/25 Newton 137-24715 NORMAN YUDKOFF, Primary Examiner. ALPHONSO SULLIVAN, Examiner. 

1. A FUEL OIL DISTILLATION PLANT COMPRISING FUEL-PROCESSING APPARATUS HAVING A BURNER, SAID APPARATUS INCLUDING FIRST MEANS FOR PRODUCING A LIQUID END PRODUCT AND A BYPRODUCT COMBUSTIBLE GAS, A U-SHAPED TRAP HAVING TWO END CONNECTIONS, SECOND MEANS COUPLING ONE OF SAID END CONNECTIONS TO SAID FIRST MEANS FOR DIRECTING SAID GAS TO SAID TRAP, SAID TRAP BEING FILLED WITH A NON-VOLATILE HYDROCARBON LIQUID, A ONE-WAY CHECK VALVE IN SAID TRAP POSITIONED TO PERMIT FLUID FLOW IN ONLY THE DIRECTION FROM SAID ONE END CONNECTION TO THE OTHER END CONNECTION, AND A PUMP HAVING AN INLET CONNECTED TO THE OTHER END CONNECTION AND AN OUTLET CONNECTED TO SAID BURNER, WHEREBY GAS PRODUCED BY SAID FIRST MEANS IS RETURNED TO SAID BURNER FOR COMBUSTION AND HEATING OF SAID APPARATUS. 